A conference call is a phone call you have with more than one other person. You can either start a conference call with several people simultaneously or add people to an existing call.
What do you want to do?
Start a conference call
To start a conference call, do the following:
Open Lync and, in your Contacts list, press and hold the CTRL key on your keyboard, click each of the contacts you want to call, or click a contact group name.
Right-click any one of the selected contacts or the group name, point to Start a Conference Call, and then click the number you want to use for the call.
Add one or more contacts to a call
To add contacts to a call, do the following:
In a conversation window, click the People Options menu, and then click Invite by Name or Phone Number.
Press and hold the CTRL key on your keyboard, click the contacts you want to call, and then click OK. Or, you can add contacts one at a time after searching for them.